PC Marine Navigation 1000nm Comparison Test

PC Marine Navigation 1000nm
Comparison Test

Introduction

There are a number of free or nearly free, marine navigation systems for the PC which are supported by forums and a loyal band of enthusiasts. I have long wondered how these systems would stand up on a long voyage over several days of sailing. Which would be best in terms of reliability and usability and is navigating using a laptop as a real alternative to a costly dedicated onboard nav systems provided by such manufacturers such as Garmin and Raymarine. The results were interesting and in some cases surprising

 

Test Objectives

To compare the:

  • Suitability,

  • Reliability

  • Accuracy

of four navigation systems in a real life situation over 1000nm and 10 days at sea.

 

Limiting factors

  • Running four navigation systems on a single netbook may have reduced performance and/or reliability.

  • I am more familiar with SeaClear and Google Earth than OpenCPN and PolarViewNS. It would have been easy to slip into the ‘easy chair’ of known software.

  • Any comparison is likely to be more subjective than objective.

  • Unable to compare commercial navigation systems due to cost with the exception of the Raymarine G80 chartplotter installed on the vessel.

  • Used differing charts formats (SeaClear: WCI , OpenCPN: Cmap 93, PolarViewNS: .KAP) so difficult to compare chart displays like for like.

  • Our vessel was not equipped with an AIS deceiver or transponder so the AIS part of the test was conducted with a live AIS feed from San Francisco.

Even with the above limiting factors it was felt that the comparison test would yield results useful for the average yachtsman (or woman)

 

 

Equipment Used

Samsung NC10 (from www.Dabs.com)

Bluetooth GPS receiver (from www.ebay.com)

Power supply 12 v to 19v (from www.ebay.com)

 

Marine Navigation Software Used

SeaClear from www.sping.com

OpenCPN From www.OpenCpn.com

PolarCom + PolarView from www.polarnavy.com

Google Earth from www.google.co.uk

 

Accessory Software Used

FransonGate To split GPs signal into four COM outputs from www.FransonGate.com

Navigator V. 1.0.12: To create kml files for Google Earth from www.geoblogspot.com

 

Charts

SeaClear:.WCI charts + georeferenced satellite
images from

PolarViewNS :( PolarView + PolarCom) .kap charts from + georeferenced satellite images from

OpenCPN: Cmap 93 charts (not legal)

Google Earth: Overlay charts

 

PC Marine Navigation systems under test

  • SeaClear v.1.0.0.205

  • OpenCPN v. 2.1.0 Build 624a

  • PolarCom + PolarView v.1.4.72

  • Google Earth with Chart Overlays v. 5.2.1.1329 (beta)


The Trip

  • Start:Bodrum (Turkey)

  • Destination: Alexandria (Egypt)

  • Return Destination:Bodrum (Turkey) via Symi and Kos (Greece)

  • Trip Length:1050 nm (Measured via track)

  • Duration: Outbound approx 4 days Inbound approx 6 days

The Vessel

  • Jeanneau 12.5 m

  • 160 watt solar panels

  • Raymarine G80 Chartplotter

  • Autohelm autopilot

  • 50 hp Yanmar diesel engine

Test Comparison Criteria.

Downloading

How easy is it to download the software and does it take a long time.

 

Installation

Is installation straightforward and safe?

 

Support

What support is available?

 

Chart Availability

Are charts easily available within the US and worldwide?

 

Installing Charts

Is it easy to install charts?

 

Documentation

Is documentation available and easy to use?

 

Connecting GPS

How difficult is it to connect to your GPS?

 

Pretrip planning

  • Route planning

  • Weather Planning

  •  

Navigation During the voyage

  • Usability

  • Positional accuracy

  • Satellite Image Support

  • Stability

  • Route Following

  • AIS Display

  • AIS Collision Warning

 

 

Test Results

SeaClear

Downloading

SeaClear was easy to download from www.sping.com (10/10)

Installation

Installation was straightforward and the installation was “self contained” in the sense that all required files are located under a SeaClear folder and the computer register is not accessed or modified. The calibration and chart installation program, MapCal, was also installed but a desktop icon was not created. This has to be created manually. MapCal is the sole method of installing charts for SeaClear (8/10)

Support

Development of SeaClear seems to have come to a halt with little direct support from the developer. The main support path is the forum http://groups.yahoo.com/group/seaclear_mapping/messages This forum is very active and supportive of SeaClear and I know the SeaClear developer, Ollie, monitors the forum and steps in with advice when needed. (9/10)

Chart Availability

SeaClear uses unencrypted BSB charts or charts in the SeaClear .WCI format. Within the US charts in the required format are freely available but outside the US legal availability is limited Companies such as 1yachtua supply charts for the Med. (7/10)

NOTE:  VisitMyHarbour now supply legal UK/Ireland/Belgium and Netherlands charts for SeaClear, with more areas coming.

Installing Charts

Installing charts was a convoluted process using the utility MapCal. Installing charts was a big support load for the SeaClear forum on Yahoo. (6/10)

VisitMyHarbour charts are pre installed saving the user any bother.

 

Documentation

Documentation is provided in the PDF format. The documentation was comprehensive but very poorly organised and presented. This has led to publications such as SeaClear Unleashed (7/10)

The VisitMyHarbour packages have a comprehensive built in help section written by the author of THIS article, Richard Fariman

Connecting GPS

Once the COM port for the GPS signal is established, connecting to SeaClear was straightforward but the BPS must be set to 4800. The input NMEA signal can be monitored via SeaClear’s System Monitor. On rare occasions SeaClear lost the input signal and had to be restarted. (8/10)

Pre-trip planning

  • Route planning

You have to enter the Route Editor mode to create and edit routes. Some problems were experienced with adding or inserting waypoints to a route but those were relatively easy to overcome. (7/10)

  • Weather Planning

Not possible with SeaClear (0/10)

Navigation During the voyage

  • Usability

The GUI of SeaClear was old fashioned and cluttered compared to the other systems. This could be improved by hiding the dashboard. (8/10)

  • Positional accuracy

For the majority of the trip SeaClear was positionally accurate. (9/10)

 

On one occasion,. I observed that SeaClear was plotting a position about 200 m to the east of my true position The boat was on the west side of the harbour and the plotted position on the east

  • Satellite Image Support

SeaClear accurately displayed georeferenced satellite images although these were not quilted.

  • Stability

SeaClear was stable throughout the whole 10 day test. (10/10)

  • Route Following

Once loaded it was easy to activate a route. If you are some distance from the route SeaClear plotted a route at right angle to the first leg to reduce XTE to a minimum as soon as possible. This may cause problems with a connected autopilot. The solution was to ensure your first waypoint is in close proximity to your vessel before you activate the route. It was only possible to have one route at a time on display. (7/10)

  • AIS Display

Connecting the AIS signal was just a matter of selecting a port via Tools/Properties and setting the speed to 38400 bps. SeaClear multiplexes its inputs into a single stream which can be seen via the System Monitor.

SeaClear quickly plotted the positions of vessels with AIS transponders.

All the AIS vessels display in the AIS list at the SeaClear Dashboard

 

The Find button locates the vessel for you, or the Info button opens an AIS Target Info dialog box

It was not possible to de-clutter the AIS display of vessels. Vessels under way and at anchor were displayed (7/10)

  • AIS Collision Warning

CPA (Closet Point of Approach)Max and TCPA (time to Closest Point of Approach) are set via Tools/Properties Setting CPA and TCPA values too high, resulted in SeaClear identifying most vessels in the area as potential collision risks with the resulting alarms
If CPA and TCPA settings are violated SeaClear sounds an audible collision warning and a collision warning displays on screen which shows the collision danger vessel name near your vessel’s position. (9/10)

 

 

 

OpenCPN

Downloading

Downloading was fast and easy from http://opencpn.org/download (10/10)

Installation

Installation was fast and trouble free. (10/10)

Support

There is a very active support forum at http://www.cruisersforum.com/forums/f134/ . As the software is being actively developed the developers monitor the forum and respond very quickly. Feature updates occur almost every month with more frequent bug fixes as required. (10/10)

Chart Availability

OpenCPN utilises BSB charts which are freely available within the US with limited availability worldwide. Cmap 93 vector charts are also supported but the use of these charts is illegal (7/10)

VisitMyHarbour are now making charts for OpenCPN and Polar Navy, available on a portable ChartStick

Installing Charts

Chart installation was quick and easy. Browse for chart directory, add it to the list and force a full database rebuild and the charts are displayed on screen. (10/10)

Documentation

Documentation is provided online but is limited (6/10)

Connecting GPS

On start up, OpenCPN automatically searches for free COM port with a valid NMEA signal. This proved to be foolproof and reliable (10/10)

Pretrip planning

  • Route planning

OpenCPN one of the best route creation tool of all the systems. Simply click a single on screen button and create your route and click to creates waypoints and the route on the chart (10/10)

  • Weather Planning

OpenCPN displays GRIB files but these have to be downloaded from a third party service or server such as the free Ugrib service. In my case I used PolarViewNS to download the files. The GRIB files were later displayed so I could weather plan my return trip (8/10)

Navigation During the voyage

  • Usability

With its clean uncluttered GUI OpenCPN was easy to use during the trip (9/10)

  • Positional accuracy

OpenCPN consistently plotted a position approx 200 meters east of the true position on the Cmap 93 charts. This was confirmed by manual position fixing. As all the software was using a common GPS signal I conclude that the position error was due to OpenCPN or and error in the Cmap 93 charts. Once the error was quantified, I could take this into account when navigating. (5/10)

NB this is a problem with the CM93 charts, OpenCPN displays VisitMyHarbour ChartStick charts accurately

  • Satellite Image Support

I could find no way of displaying BSB (.kap file) charts alongside Cmap 93 so could not test satellite image support. So at present I assume it is not supported (0/10)

  • Stability

On the whole OpenCPN was stable during the test and only crashed twice during the 10 day trip (8/10)

  • Route Following

To activate and follow a route, the route or waypoint is right clicked and ‘activate route’ selected. The nearest way point flashes to confirm activation. A navigation window displays with XTE, BRG, RNG and TTG. (9/10)

  • AIS Display

AIS connection was easy to achieve via the AIS tab of Toolbox

 

OpenCPN quickly plotted the positions of vessels with AIS transponders.

Right clicking any AIS target opens the AIS Target Query dialog box

 

Or, all AIS targets within range could be displayed in the AIS Target list dialog box

It was possible to de-clutter AIS display via the ToolBox/ AIS Tab. In particular vessels at anchor could be removed from the display ((9/10)

  • AIS Collision Warning

In a potential collision situation OpenCPN sounded a raucous audible alarm and an transparent alarm screen displays identifying the vessel in question The alarm has to silenced or acknowledged .

In addition the potential collision risk vessel is identified on the chart display.(9/10)

 

 

PolarViewNS

Downloading

Downloading was straightforward from http://www.polarnavy.com/main/shop with the offer of a free trial with up to 5 activations. (10/10)

Installation

Installation of the two PolarViewNS components (PolarView + PolarCom) was easy with no problems (10/10)

Support

There is a support forum but seems to have little activity. Help via email is available and replies were received within a few hours (8/10)

Chart Availability

Charts are easily available within the US in RNC and ENC formats. There is limited availability outside of US waters. BSB charts are supported where available. (7/10)

VisitMyHarbour are now making charts for OpenCPN and Polar Navy, available on a portable ChartStick

Installing Charts

Installing charts was just a case of browsing for a chart directory and PolarView did the rest. (10/10)

Documentation

Documentation is provided online but is limited (6/10)

Connecting GPS

Connecting to the GPS was just a case assigning the port a name and a COM port number. This was done within PolarCom. The port with id of 0 was reserved for connection to PolarView. (8/10)

 

Pretrip planning

  • Route planning

Route creation was just a case of shift clicking and the chart to create waypoints. Each leg of the route was labelled with the bearing and distance to the next waypoint. (10/10)

 

 

  • Weather Planning

PolarViewNS was the only system that allowed direct downloads of GRIB files. An area is selected on the chart and the downloads were from a dedicated server that had acceptable download speed. The files were automatically saved to allow for weather planning and later display during the trip . I used the GRIB file display to plan the return trip to take advantage of wind shifts in our favour. As I needed to go NW and the prevailing winds were NW any advantage due to wind shifts S or W took hours off my trip(10/10)

Navigation During the voyage

  • Usability

The GUI for PolarViewNS was the cleanest and clearest of all the systems under test. The instrument display of PolarCom was outstanding and clearly visible from the helm. (9/10)

 

  • Positional accuracy

PolarViewNS was 100% accurate at all time during the trip.(10/10)

  • Satellite Image Support

PolarViewNS accurately displayed georeferenced satellite images and these were quilted with the BSB charts (10/10)

 

PolarViewNS also has a search and download feature that searches for images for a selected area and quilts the image with the existing BSB charts,

  • Stability

PolarViewNS was stable throughout the 10 day test. (10/10)

  • Route Following

Activating a route was as simple as selecting it from a list in Route Manager. Once activated data was transferred to PolarCom for large instrument display and for use with the various alarms such as anchor alarm, waypoint arrival act (9/10)

  • AIS Display

Connection to the AIS signal was via the Configure option in PolarCom

All AIS targets within range we plotted by PoarViewNS and clicking on the target displayed some limited data about the vessel.

A list of all AIS targets displayed all available AIS data of vessels within range.

It was possible to declutter AIS display from within PolarCom. (9/10)

 

  • AIS Collision Warning

CPA and TCPA are set from within PolarCom

If the CPA and TCPA values are infringed an audible alarm sounds and an Alarm dialog box opens.

Collision risk vessels are highlighted in red on the chart.

And highlighted in red in the AIS Vessel List dialog box (9/10)

 

 

 

 

Google Earth (with Navigator)

Downloading

Downloading from Google was straightforward but took several minutes. (Disable the Chrome download option to save time) (9/10)

Installation

Installation was straightforward but involved downloading several large files from Google (9/10)

Support

There are a vast number of third party sites that provide support for Google Earth as well as Google themselves (10/10)

Chart Availability

Not 100% applicable as Google Earth is image based but BSB charts are available to overlay Google Earth from 3rd party vendors. Available for within the US but less available for outside US waters (7/10)

NB: VisitMyHarbour make VisiCharts (Uk and Ireland) that work with Google Earth

 

Installing Charts

Once obtained, as simple as opening a .KMZ or .KML file within Google Earth (10/10)

Documentation

There is a vast amount of documentation easily accessible. (10/10)

Connecting GPS

I failed to connect the Bluetooth GPS directly to Google Earth so connected via Navigator which was easy. (8/10)

Pretrip planning

  • Route planning

Routes were easy to import in the GPX format and Navigator added the feature of a waypoint arrival alarm. If you visit each of your destinations when connected to the internet the satellite imagery is saved to cache for later use offline (9/10)

  • Weather Planning

Although GRIB files are at present not supported, there are many sources of weather data available to Google Earth (9/10)

Navigation During the voyage

  • Usability

I constantly fell back to using Google Earth during the trip particularly when in proximity to land. The images gave a clear indication as what to expect when entering a harbour and the terrain feature helped with identifying the profiles of coastlines and islands. (9/10)

  • Positional accuracy

Google Earth was 100% accurate when compared to the other PC based systems and to the Raymarine G80 onboard. (10/10)

 

  • Satellite Image Support

As Google Earth is an image based program it is no surprise that it out shone the other system. I was able to plot my position on high definition images and easily identify islands and coastlines. (10/10)

 

 

  • Stability

There is a bug with Google Earth in that if the PC hibernates with Google Earth running the computer crashes on restart. This proved not to be a problem as I disabled hibernation and just turned off backlighting to preserve battery power.

Google Earth was very hard on CPU and memory resources but did not crash the PC in normal use. (7/10)

  • Route Following

Although not strictly route following Google Earth could be set to “fly to” each of the waypoints on the route. (5/10)

 

  • AIS Display

It is not possible to directly connect an AIS signal to Google Earth. With an internet connection third party providers supply AIS data in a form that can be displayed in Google Earth. (5/10)

  • AIS Collision Warning

This is not possible in Google Earth (0/10

 

 

Feature Comparisons

SeaClear

OpenCPN

PolarViewNS

Google Earth (with Navigator)

RayMarine G80

Feature

Free

Free

39.99 USD

Free

1500 USD

Price

Yes

Yes

Yes

Yes

N/A

Windows: XP ,Vista, 7

Under Wine

Yes

Yes

Under Wine

N/A

Linux

No

Yes

Yes

No

N/A

Mac

Yes

Yes

Yes

No

Yes

MOB

Yes

No

Yes

Yes

Yes

XTE Alarm

Yes

No

Yes

Yes

Yes

Waypoint Alarm

Yes

No

Yes

No

Yes

Depth Alarm

No

Yes

Yes

Yes

Yes

Anchor Alarm

No

No

Yes

No

No

GRIB Download

No

Yes

Yes

No

No

GRIB Support

No

Yes

Yes

Yes

Yes

GPX in

No

Yes

Yes

No

Yes

GPX out

Yes

Yes

Yes

Yes

N/A

Mouse Zoom

No

Yes

No

No

N/A

Auto COM Detect

No

Yes

Yes

No

Yes

Vector Chart

Yes

Yes

Yes

Yes

No

Raster Charts

No

Yes

No

No

No

Cmap 93

No

No

Yes

No

Yes

Large Instrument Display

Yes

Yes

Yes

Yes

No

AIS Display

Yes

Yes

Yes

No

No

CPA Alarm

Yes

Yes

Yes

Yes

No

Sat' Image Display

Yes

Yes

No

No

Yes

Autopilot Output

Yes

Yes

Yes

No

Yes

Night Palette

No

Yes

Yes

Yes

Yes

Course Up

No

Yes

Yes

No

Yes

Chart Quilting

No

Yes

Yes

No

No

Tides

No

Yes

Yes

No

No

Currents

Yes

No

No

No

No

Fuel Consumption

Yes

No

Yes

No

No

Image/Chart Calibrate

No

No

Yes

No

No

Chart/Image Download

No

Yes

Yes

Yes

No

Online Help

Yes

No

No

No

No

DR Mode

No

No

Yes

No

No

Triangulation Fix

 

Conclusions

All the software did its job, and was usable, stable and reliable throughout the trip and test period. The ideal software would have been the best features from each package combined into a super hybrid system.

SeaClear proved to be reliable and accurate but suffered from an outdated user interface that seems to have been developed piecemeal. All the features were there but not easy to access hampered by poor documentation. SeaClear was not safely usable at the helm using our netbook but perfect for chart table use.

OpenCPN was reliable and accurate and had a clean uncluttered user interface that maximised chart display real estate. The use of CMAP 93 charts gave a clear vector based display but the use of these charts is difficult legally for the average yachtsman. OpenCPN was the easiest to use for route creation. Again it was not possible to use OpenCPN safely at the helm using our netbook but perfect for chart table use.

PolarViewNS (PolarView + PolarCom) was the only software that had to be paid for (currently around 30USD) PolarViewNS had a clean uncluttered user interface that maximised chart display real estate. Route creation was bit quirky and the omission of mouse wheel zooming frustrating. Chart quilting was truly amazing with charts of differing scales being accurately quilted and displayed. Even Georeferenced satellite images were quilted correctly.PolarCom was the star of the show with clear large scale instrument display visible from the chart table to the helm.

PolarViewNS was the only system under test that was safely usable at the helm using our netbook as well as at the chart table.

Google Earth (with Navigator): was never intended to be a navigation system, but with the inclusion of Navigator our position was accurately plotted via GPS and even an anchor alarm could be set(SeaClear users weep) Using BSB chart overlays our position was plotted over semi transparent chart with the satellite imagery showing though. With terrain turned on, Google Earth allowed us to identify islands, and coastlines by their outlines. Again not safely usable at the helm using our netbook but perfect for chart table use.

Comparison with Onboard Navigation System (Raymarine G80

The PC based systems proved as reliable and on occasions more reliable then the G80

  • The power requirements of the netbook and the G80 were approx the same.

  • The PC based charts had greater detail

  • Zooming was easier than the G80

  • Scrolling was easier than the G80

  • Route planning was easier than the G80

  • With the PC based systems it was easy to plan at home and transfer the data to the onboard system.

  • Unlike the G80 weather planning was possible on three of the PC based systems (OpenCPN PolarViewNS and Google Earth)

  • At slow speeds < 2 knots the position and COG plotted by the G80 was unstable and at about 1 knots unusable. The PC based system seemed to use better damping algorithms as lower speeds to eliminate this problem.

A Clear Winner?

If I was forced to pick a clear winner it would have to be PolarViewNS. With is large, accurate and programmable instrument display, that could be clearly read from the helm to the chart table on the 12.5 mt vessel, it overcame the common limitation of PC based systems that previously meant they could not be safely used at the helm. Away from the coast or other hazards I was able to sail efficiently just using the PolarCom instrument display of COG, SOG and VMG.

The Future

The dark horse in marine navigation has to be Google Earth. It is possible now to overlay BSB charts over the satellite images of Google Earth to give accurate depth data. Away from an internet connection Google Earth runs very happily using its stored cache data. There must be some software developers out there working on navigation system based on Google Earth, or perhaps Google is doing it itself. Dedicated chartplotter manufacturers beware.

Imagine a system that includes marine navigation, GPS, AIS, internet connectivity, email, audio, video cheap charts, and satellite imagery all for the price of low cost netbook or laptop.

Postscript (A semi emergency)

During the return voyage, close hauled in 22knts of wind and in close proximity to Rhodes, our onboard Raymarine G80 Chartplotter crashed and failed to restart after a reboot. I fell back on the PC based systems I had onboard and sailed on using the instrument display of PolarCom. In the light of day the chartplotter problem proved to be only a stuck button and easily fixed. The incident brought home the need of having backup systems onboard and not being too reliant on a single system (and that things always look better in daylight)

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Article Info

Author:
Richard Fairman
Category:
Overview: Comparison of nav programs and chart types
Added:
24/08/2012
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